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US 4,836,338 AGranted
Electrically operated disc brakes
AssigneeAllied-Signal Inc.
InventorAlistair G. Taig
Life of this patent
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AssigneeAllied-Signal Inc.
InventorAlistair G. Taig
Estimating the term…
The electrically operated disc brakes (10, 210) may include a high efficiency screw and nut mechanism (60) and/or a one-way clutch mechanism (230). The high efficiency screw and nut mechanism (60) includes a screw (86) with a screw thread (89) that has a predetermined pitch, and at least one nut (77, 97) disposed about the screw (86) and having an interior opening (78, 98) with a nut thread (79, 99) therein. The pitch of the nut thread (79, 99) is equal to the pitch of the screw thread (89), and the pitch diameter of the nut thread (79, 99) is greater than the pitch diameter of the screw thread (89). The screw (86) is driven by the electric motor (40) of the disc brake (10, 210). The one-way clutch mechanism (230) includes a sun gear drive member (252) which has oppositely disposed radial drive slots (257) through which extends a drive pin (243) that extends transversely through the drive shaft (241) of the electric motor (240). The sun gear drive member (252) is journalled within a cage member (281) which has oppositely disposed radial cage slots (282) into which extends the drive pin (243). The radial cage slots (282) are in circumferential non-alignment with the radial drive slots (257) of the sun gear drive member (252). The sun gear drive member (252) includes cam surfaces (253) receiving roller bearings (290) thereat, the roller bearings (290) extending through oppositely disposed openings (284) within the cage member (281) to engage at interior surface (297) of an annular housing (295). The clutch mechanism (230) permits the sun gear drive member (252) to be rotated in both directions by the drive shaft (241), but when reaction forces attempt to reverse rotation of the drive member (252) and electric motor (240), the clutch mechanism (230) locks and prevents such reverse rotation.
A disc brake that may be operated by motor means, comprising a caliper having a bore with an actuating mechanism disposed therein, the actuating mechanism and caliper actuatable to displace a pair of friction elements into engagement with a rotor, the actuating mechanism including a one way clutch mechanism connected with a drive shaft of said motor means, the clutch mechanism comprising the drive shaft having a transverse drive pin extending therefrom, the drive shaft and drive pin received within a drive member which has radially extending drive slots, the drive pin extending through said drive slots, a cage member disposed about said drive member and having therein a pair of oppositely disposed radial cage slots, the drive pin extending into the radial cage slots, the drive member including cam surfaces thereabout receiving bearing means thereat, and a housing disposed about said cage member and having an interior surface engaged by said bearing means, whereby rotation in one direction of said drive member by the actuating mechanism causes said bearing means to engage between said cam surfaces and interior surface of the housing in order to fix nonrotatably the drive member, and rotation of the drive member by the drive shaft in the one direction causes said drive pin to engage radial abutment surfaces of the radial cage slots to effect rotation of the cage member and cause said bearing means to move to non-engagement with said housing and permit continual rotation of said drive member in the one direction to effect operation of the actuating mechanism.
A disc brake that may be operated by motor means, comprising a caliper having a bore and a piston housing actuatable to displace a pair of friction elements into engagement with a rotor, motor means for actuating operatively a high efficiency screw and nut mechanism, the screw and nut mechanism effective to displace axially said piston housing and cause the displacement of the pair of the friction elements, the screw comprising a screw thread having a predetermined pitch and a predetermined pitch diameter, a first nut disposed about said screw and having an interior opening with a nut thread disposed therein, the nut thread engaging at a circumferential portion thereof the screw thread, the nut thread having a pitch equal to the predetermined pitch of the screw thread, the nut thread having a predetermined pitch diameter greater than the predetermined pitch diameter of the screw thread, so that rotation of said screw by the motor means effects rotation and axial displacement of said first nut to effect said axial displacement of the piston housing, a bearing race member disposed within said piston housing and including a bearing race, the first nut including a complementary-shaped bearing race and bearing means disposed between the bearing races, whereby the rotation and axial displacement of the nut effects axial displacement of the bearing race member against the piston housing, the piston housing comprising an annular member with an interior opening therein, the first nut, screw, bearing race member, and bearing means disposed within the interior opening of the piston housing, a second nut disposed within the interior opening of the piston housing, the second nut having an interior opening with a second nut thread disposed thereabout, the second nut thread engaging at a circumferential portion thereof the thread of the screw, the second nut thread having as pitch equal to the predetermined pitch of the screw thread and a pitch diameter greater than the predetermined pitch diameter of the screw thread, a thrust race member disposed within the interior opening of the piston housing, the thrust race member disposed axially between the nuts and including therein a bearing race, the second nut having a complementary-shaped bearing race and a bearing mechanism disposed between the bearing races of the thrust race member and second nut and a sleeve member disposed between the thrust race member and bearing race member, the sleeve member including an interior opening and disposed about said first nut, rotation of the screw effecting rotation and axial displacement of the second nut against the thrust race member which transmits axial displacement, via the sleeve member, to the bearing race member and piston housing.
A disc brake that may be operated by motor means, comprising a caliper having a bore and a piston housing actuatable to displace a pair of friction elements into engagement with a rotor, motor means for actuating operatively a high efficiency screw and nut mechanism, the screw and nut mechanism effective to displace axially said piston housing and cause the displacement of the pair of the friction elements, the screw comprising a screw thread having a predetermined pitch and a predetermined pitch diameter, a first nut disposed about said screw and having an interior opening with a nut thread disposed therein, the nut thread engaging at a circumferential portion thereof the screw thread, the nut thread having a pitch equal to the predetermined pitch of the screw thread, the nut thread having a predetermined pitch diameter greater than the predetermined pitch diameter of the screw thread, so that rotation of said screw by the motor means effects rotation and axial displacement of said first nut to effect said axial displacement of the piston housing, a bearing race member disposed within said piston housing and including a bearing race, the first nut including a complementary-shaped bearing race and bearing means disposed between the bearing races, whereby the rotation and axial displacement of the nut effects axial displacement of the bearing race member against the piston housing, the piston housing comprising an annular member with an interior opening therein, the first nut, screw, bearing race member, and bearing means disposed within the interior opening of the piston housing, second nut disposed within the interior opening of the piston housing, the second nut having an interior opening with a second nut thread disposed thereabout, the second nut thread engaging at a circumferential portion thereof the thread of the screw, the second nut thread having as pitch equal to the predetermined pitch of the screw thread and a pitch diameter greater than the predetermined pitch diameter of the screw thread, a thrust race member disposed within the interior opening of the piston housing, the thrust race member disposed axially between the nuts and including therein a bearing race, the second nut having a complementary-shaped bearing race and a bearing mechanism disposed between the bearing races of the thrust race member and second nut, a sleeve member disposed between the thrust race member and bearing race member, and the disc brake further comprising a clutch disposed between the first nut and sleeve member, the clutch permitting said first nut to rotate freely in one direction and preventing rotation, absent rotation of the screw, in an opposite direction.
Dependencies are inferred from the claim text.